Bifunctionality of Carbon Nanotubes – Chitosan Film Based Biosensor for Selective Determination of Atropine in Biological Fluids and Leaf Extract of Datura Stramonium

2021 ◽  
Vol 87 (12) ◽  
pp. 11-16
Author(s):  
E. I. Shinko ◽  
O. V. Farafonova ◽  
T. N. Ermolaeva

Conditions for the preparation of carbon nanomaterials for embedding into the discerning layer of a piezoelectric immunosensor are described. The effect of the oxidation method, temperature, and the duration of treatment of nanomaterials with an oxidizing agent on the surface concentration of active functional groups is demonstrated. It is shown that the use of carboxylated carbon nanotubes (CNT) increases the efficiency of their binding to biomolecules and increases the stability of the discerning layer of a piezoelectric sensor when measurements are carried out in liquid media. Conditions for the determination of antibiotics using piezoelectric immunosensors modified with carbon nanomaterial were studied including the choice of immunoreagent concentrations and assessment of the selectivity of antibiotic determination. The CNT-based piezoelectric immunosensors providing rapid, highly sensitive, and selective determination of the analyte at the MRL level and below it in food products and biological fluids are proposed.


2001 ◽  
Vol 84 (2) ◽  
pp. 368-375 ◽  
Author(s):  
Mohammed Rizk ◽  
Fathalla Belal ◽  
Fawiza Ibrahim ◽  
Soad Ahmed ◽  
Zeinab A Sheribah

Abstract A derivative UV-spectrophotometric analytical procedure was developed for determination of three 4-quinolone antibacterials: norfloxacin (NFX), ciprofloxacin (CFX), and sparfloxacin (SFX). The method depends on the complexation of Cu(II) with the studied compounds in aqueous medium. A third order, measurement was applied for their quantification. A linear correlation was established between the amplitude of the peak and concentration for all the studied drugs in the range of 15–80, 35–120, and 200–700 ng/mL, with minimum detectability (S/N = 2) of 1.0, 1.3, and 5.1 ng/mL for NFX, CFX, and SFX, respectively. The method was successfully applied for accurate, sensitive, and selective determination of the studied drugs in bulk and tablets formulation with average percentage recoveries of 99.22 ± 0.55 to 100.33 ± 1.60. The results obtained were favorably compared with those of the reference method. The method was also used to determine sparfloxacin in spiked human plasma and urine. The results obtained were satisfactory, accurate, and precise.


Biomolecules ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 294 ◽  
Author(s):  
Tian ◽  
Deng ◽  
Wu ◽  
Ding ◽  
Li ◽  
...  

In this paper, a tryptophan (Trp) molecularly imprinted chitosan film was prepared on the surface of an acetylene black paste electrode using chitosan as the functional polymer, Trp as the template molecule and sulfuric acid as the crosslinking agent. The surface morphologies of non-imprinted and imprinted electrodes were characterized by scanning electron microscopy (SEM). The formation of hydrogen bonds between the functional polymer and the template molecule was confirmed by infrared spectroscopy. Some factors affecting the performance of the imprinted electrode such as the concentration of chitosan, the mass ratio of chitosan to Trp, the dropping amount of the chitosan-Trp mixture, the solution pH, and the accumulation potential and time were discussed. The experimental results show that the imprinted electrode exhibit good affinity and selectivity for Trp. The dynamic linear ranges of 0.01–4 M, 4–20 M and 20–100 M were obtained by second derivative linear sweep voltammetry, and the detection limit was calculated to be 8.0 nM. The use of the imprinted electrode provides an effective method for eliminating the interference of potentially interfering substances. In addition, the sensor has high sensitivity, reproducibility and stability, and can be used for the determination of Trp in pharmaceutical preparations and human serum samples.


Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 673
Author(s):  
Heba M. Hashem ◽  
Saad S. M. Hassan ◽  
Ayman H. Kamel ◽  
Abd El-Galil E. Amr ◽  
E. M. AbdelBary

A simple, efficient and reliable analytical method was developed and used for the determination of the fluvoxamine drug (FLV) in pharmaceutical preparations and biological fluids. The method is based on the cost-effective screen-printed platform for the potential transduction of the drug. Host-tailored molecular imprinting polymer (MIP) was integrated with the potentiometric platform as a recognition receptor, in which FLV, acrylamide (AAm), ethylene glycol dimethacrylate (EGDMA) and acetonitrile were used as a template, functional monomer, cross-linker, and solvent, respectively. MIP particles were dispersed in plasticized poly (vinyl chloride) (PVC) and the membrane was drop-casted on carbon screen-printed electrode. The MIP, in addition to non-imprinted polymers (NIP), was characterized and the binding experiment revealed high affinity and adsorption capacity of MIP towards FLV. The proposed sensor displayed near-Nernstian cationic slope of 55.0 ± 0.8 mV/decade (r2 = 0.999) with a low detection limit of 4.8 × 10−6 mol/L over a wide pH range (3.0–8.5). The electrochemical features of the proposed sensors including electrochemical impedance spectroscopy (EIS) and chronopotentiometry measurements (CP) in the presence of multi-walled carbon nanotubes (MWCNTs) as a solid contact transducer were also investigated. The applications of the proposed sensor for the determination of FLV in different dosage forms with recovery values (98.8%–101.9%) and (97.4%–101.1%), respectively compared with the reference HPLC method with acceptedFandt-student tests values at the 95% confidence level.


Sign in / Sign up

Export Citation Format

Share Document